高光谱图像深度模糊核聚类的洋底锰结核识别

目的 海洋资源调查是海洋科学研究的重要组成部分，对于开发利用海洋资源、保护海洋环境有重要意义。将深海高光谱图像用于调查洋底锰结核资源，相比传统图像方法信息更为全面，识别更为准确。但是高光谱方法中用于有监督分类识别的分类器需要人工标定的标签，这在深海环境中是较为困难的。针对这一局限性，本文提出了一种融合深度网络与模糊核聚类的深度模糊核聚类（deep kernel fuzzy C-means，DKFCM）算法，实现对洋底锰结核高光谱图像的无监督聚类。方法 DKFCM由随机深度卷积网络（Rdnet）及改进的模糊核聚类算法两大模块组成。Rdnet通过降维、随机图块卷积及非线性激活操作的循环，实现对高光谱图像浅层及深层特征的提取，融合这两类特征作为后续聚类识别的输入。改进的模糊核聚类算法先用欧氏距离计算初始聚类中心，再用模糊核聚类的方法以实现海洋资源的准确分类。结果 实验结果表明，DKFCM无监督聚类能有效聚类洋底资源，对锰结核的聚类准确率达到76.59%，相比单用K-means聚类提高了20.99%，相比经Rdnet提取特征后再用K-means聚类提高了13.76%，对比实验表明DKFCM算法在无标签数据的情况下也能达到良好的准确率。结论 本文所提的高光谱深度模糊核聚类方法，实现了深海锰结核的无监督聚类，可以用于海洋资源量的评估。     

长期循环荷载作用时单桩式海上风力机结构自振频率的影响规律研究

基于FLAC^3D有限差分计算平台,建立风力机结构自振频率数值计算模型,并与工程监测的自振频率数据进行对比验证模型的有效性;然后通过嵌入土体刚度衰减模型（DSM）,考虑长期循环荷载对地基刚度的影响;探讨不同大小的循环荷载、不同的循环加载次数对海上风力机结构体系自振频率的影响规律,提出自振频率衰减公式;最后结合既有的风力机结构体系自振频率简化计算方法,建立单桩式海上风力机长期自振频率简化评价方法。结果表明,循环荷载的增大、加载次数的增加会导致海上风力机结构体系自振频率较小;风力机结构体系的设计自振频率应偏移3P,以保证海上风力机的长期运营安全。     

对变量组合法的改进

对变量组合法进行了改进,使多困难度几何规划中对偶变量分离问题简单易解．     

Control of cone-jet geometry during electrospray by an electric current

A new electrospray system has been successfully developed by employing a proportional–integral–derivative control action to maintain an electric current at a certain value. A polymer precursor solution containing polyethylene glycol was used to examine the performance of this system. The result showed that cone-jet geometry could be controlled easily by adjusting the electric current. The length of the cone-jet decreased as the electric current was increased, in a correlation that followed power law. We also found that the cone-jet observed during electrospraying was stable and robust with no disturbance during long periods of use (up to 4000 s). The present study is very useful for further development of high precision aerosol generators and particle synthesis.     

带负系数几何规划的一维探索法

对带负系数几何规划的多困难度情况提供了一个有效的方法，首先即利用Ｄｕｆｉｎ公式，采用集约缩并法，将带有负系数的几何规划化为正项几何规划，进一步化为Ｄ维线性规划，最后化为一维探索问题．结果表明，该方法十分有效．     

结构力学综合训练方案的教学实践

介绍了结构力学综合训练方案，指出综合训练方案是提高学生计算能力、理论水平和分析解决实际问题能力的有效途径．     

丙烯酸酯橡胶和聚氯乙烯共混体系阻尼特性的研究

论述丙烯酸酯橡胶和聚氯乙烯共混比例和工艺条件等对共混胶料的静、动态力学性能的影响。结果表明，共混物在－10℃和80℃呈现出两个阻尼峰，并使两峰间的阻尼值有所提高。这一新型共混材料已在某些领域里获得了应用。     

Ion-induced nucleation rate measurement in SO2/H2O/N2 gas mixture by soft X-ray ionization at various pressures and temperatures

This paper reports the systematic investigation of ion-induced nucleation rate measurement in a SO₂/H₂O/N₂ gas mixture, employing soft X-ray at different pressure and temperature levels. Experiments were conducted using a modified continuous flow gas-generation system employing a soft X-ray ionizer and a particle counter, with an improved integrated online temperature, pressure and a relative humidity (RH) control system. Nucleation rates were measured as a function of SO₂ concentration at different levels of RH, pressure (600–970 hPa) and temperature (5–25 °C). The results show that the nucleation rate dependence on SO₂ concentration followed a power law, and the slope varied slightly in a range from 1 to 1.26 at different RH levels (15–60%). A positive pressure effect was generally found and a power law was followed with varied scaling for different SO₂ concentrations. The trend of an increase in nucleation rate with temperature was consistent with observations in homogenous nucleation experiments, and with the behavior predicted by classical binary nucleation theory. These experimental results will be useful to explain the contribution of ion-induced nucleation in different locations and atmospheric conditions.     

Synthesis of mesoporous SnO2 spheres via self-assembly and superior lithium storage properties

This paper firstly reported a simple route to prepare SnO₂ mesoporous spheres for lithium ion battery. Mesoporous SnO₂ spheres in range of 100–300 nm were prepared by primary reaction at 353 K for 30 min, and calcination process at 773 K, which could be scaled up for manufacturing. The nano-size effect of the small particle and the 3D mesoporous structure promoted the electrolyte and lithium ion transfer and suppressed the volume changes, which greatly enhanced the cycle performances. As the anode material, it could deliver 761 mAh g⁻¹ capacity after 50 cycles at the current density of 200 mA g⁻¹. Even at 2 A g⁻¹, it retained 480 mAh g⁻¹ after 50 cycles. Furthermore, we suggested that the high stability of the structure was responsible for the improved cycle properties.